1. Technical Field of the Invention
The invention relates to a device for the determination o the alcohol content and/or the calorific value of fuels by measuring the characteristics of the fuel in a measurement cell having a flow body that is at least partially wetted by the fuel arranged therein
2. Discussion of the Related Art
In light of diminishing fossil energy reserves of fuels obtained from crude oil and stricter environmental protection requirements, increasing amounts of methyl or ethyl alcohol are being added to these fuels. Thus, any arbitrary refueling should be possible both with pure fuels and mixed fuels. When the alcohol content is higher, it is necessary to know the blending ratio in order to obtain optimal performance from the fuel-burning engine and to enable a precise proportioning of fuel adjusted to the operating conditions. The continuous determination of the alcohol content in the fuel fed into the fuel-burning engine in operation presents special problems for automobile engines in which any possible blend may be present by arbitrary refueling with various types of fuel.
In the German patent application P38,10808.9, a device of the aforementioned kind is described in which the characteristics of the fuel are measured in a measurement cell and processed in a suitable circuit. This circuit in turn is connected to an injection computer whose results are evaluated in order to control a fuel proportioning device.
It has been demonstrated that in measuring devices of this kind, high measurement accuracy and fast availability of measured values is mandatory in order to adjust fuel proportioning to the rapidly changing operating conditions.
Accordingly, it is an object of the present invention to provide a device for the determination of the alcohol content and/or of the calorific value of fuels which enables the measured values to be supplied rapidly with high accuracy of measurement.
Other objects and advantages of present invention are apparent from the drawing and specification will follow.